You may think that being a guest lecturer on a cruise ship is a dream job. I know that's what I thought when I first started giving shipboard presentations on astronomy 12 years ago.
It's not a bad gig, for sure; you travel the world, sometimes sailing to exotic places you otherwise never would visit. Your cabin is made up twice a day by an attentive steward. You can eat your fill of satisfying or -- even better -- gourmet fare around the clock (delivered directly to your stateroom if you wish) and never need to cook, or wash a dish. You might work three hours a week and have people applaud at the end of every hour.
Because all types of cruise lines use guest speakers, it's also a great way to experience the gamut of cruising styles. I've given presentations aboard large ships (Celebrity, Holland America, Princess, Royal Caribbean) and small ships (including a transatlantic voyage on a 177-foot, three-masted motor yacht for Travel Dynamics International), luxury ships (Regent Seven Seas, Seabourn, Silversea) and spartan excursion vessels (Cruise West) that sail to places larger ships could never go. I've traveled in all kinds of accommodations, even on the same cruise line (including Queens Grill, commoner and staff accommodations on Cunard), and dined with companions wearing tuxedos (Crystal), cruisers in "country club casual" togs (Oceania) and those who were shirtless (Windjammer Barefoot).
But, if your idea of a job includes getting a paycheck, you'll quickly realize that working as a guest lecturer is not a job at all. Paid guest speakers are a thing of the past, and sometimes, even celebrities only get airfare and a guest suite. In fact, many presenters pay out of pocket for the privilege of lecturing onboard.
If you want to be a cruise ship lecturer, you have to face the fact that guest speakers are among the few people aboard who are working for the ship without being paid. (Folks do come up with creative ways to make money off the cruise; I've seen authors sell copies of their books onboard, and travel photographers and writers use the trips to gain affordable shooting and research opportunities.)
That said, if you're a dynamic speaker with knowledge and passion about a topic, lecturing on a cruise ship can be a great way to educate people while you explore the world. But, guest lecturing should not be seen as an easy path to a free cruise. Nor should the lack of payment make you think that it's an easy gig anyone can do. You'll need talent and skill to stand out in the competitive hiring process. Rank amateurs need not apply.
Specialized talent agencies and the cruise lines that use them put hundreds of guest speakers on passenger ships every year. These speakers generally fall into two categories: destination lecturers, who present topics related to the ship's itinerary; and enrichment lecturers (also called special-interest lecturers), who may talk about anything else the cruise line thinks the passengers will find interesting.
Duties typically include giving two or three 45-minute presentations a week; guest lecturers are typically not called on to host dinner tables or assist with other shipboard programs.